Propulsive tail propeller assembly or tail duct fan assembly with cyclic and collective control and/or a method of thrust vectoring for aircraft maneuvering and for helicoptor single rotor head anti torque

Abstract

A method of aircraft propulsion and control more specific to rotorcraft propulsion and control using forward, neutral and aft thrust in addition to forward / aft thrust coupling from the propulsive tail assembly through cyclic and collective pitch of the non-flapping, ridged propeller / fan blades and / or from a turbojet / turbofan vectored thrust system. The cyclic blade pitch induces a drive shaft bending moment that is used to provide aircraft directional control and also provides anti-torque control for a single rotor head helicopter. The forward / reverse collective thrust actuator, phase lag elevator effect cyclic actuator and phase lag rudder / anti-torque effect cyclic actuator do not require complex control mixing. The vectored thrust system also provides aircraft directional control and anti-torque control individually or combined with the propeller / fan assembly. This assembly eliminates the requirement of rudder or elevator control on a fixed wing aircraft and the requirement of a tail rotor on a conventional helicopter while increasing speed and maneuverability. A slowed or stopped ridged X-wing rotorcraft hub with a modified circular arc airfoil would not require cyclic / collective control.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to an aircraft propulsion and control system, and more specific to a rotorcraft propulsion and control system for propeller / fan blade pitch control that induces a drive shaft bending moment and / or a turbojet / turbofan vectored thrust system that is used to provide aircraft directional control and also provides anti-torque control. This system also provides all of the forward, neutral and aft thrust required for a rotorcraft to rapidly accelerate to full speed after transitioning from hover and then to rapidly decelerate back to hover from a forward or reverse flight direction.[0002]Current rotorcraft are limited by speed, maneuverability, altitude or lift efficiency. Helicopters have a high lift efficiency because of their large disc area which results in a low disc loading but are limited in speed, maneuverability, altitude and range. These problems are caused by dissymmetry of lift, the high angle of nose pitch, drag fr...

AI Technical Summary

Benefits of technology

The present invention is an aircraft propulsion and control system that uses rigidly mounted propeller / fan blades to generate cyclic and collective pitch for aircraft maneuvering and helicopter anti-torque. The system eliminates the use of low-speed rudder or elevator control, main rotor control, and helicopter tail rotor control. The internal turbo shaft engine(s) provides power to the main rotor shaft through rotation and drives the main rotor hub for vertical hover lift, sustained flight lift, or propulsive tail propeller / fan drive shaft for forward or reverse propulsion and maneuvering control. The technical effects of the invention include improved efficiency, higher maneuverability, reduced weight, and easier control of the helicopter.

Problems solved by technology

Current rotorcraft are limited by speed, maneuverability, altitude or lift efficiency.

Helicopters have a high lift efficiency because of their large disc area which results in a low disc loading but are limited in speed, maneuverability, altitude and range.

These problems are caused by dissymmetry of lift, the high angle of nose pitch, drag from the rotor disc and the low percentage of lift produced from the inner span of the rotor blades.

Tilt rotors have a lower lift efficiency because the disc area is divided into two smaller disc's which results in higher disc loading.

This requires more power to achieve the same amount of lifting force as a rotorcraft with a single large disc area and causes instability because the disc's are out of plane with the center of gravity.

The problem that occurs with a prop rotor used for vertical lift and propulsion is the drag from the wing when in hover and the drag from the large disc's when in forward flight.

A wing would be the most efficient solution of reaching high speed, altitude and range but would increase weight and vertical lift drag.

A coaxial helicopter would eliminate dissymmetry of lift but would increase weight and drag.

Compound helicopter's combine some of the advantages of these features but are penalized by the same decrease in performance associated with them.

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